Alkoxy trifluoromethylaniline compounds

ABSTRACT

N-alkyl substituted 5-alkoxy-2-nitro-4-trifluoromethylanilines and their thio analogues. The compounds are useful as herbicides and can be formulated with conventional herbicide carriers.

United States Patent 091 [1 1 3,716,585 Strong et al. Feb. 13, 1973 54ALKOXY [56] References Cited COMPOUNDS 3,403,180 9/1968 Soper ..260/577lnventow Philip Slrong; Don Hunter, 3,332,769 7/1967 Soper 260/577 xboth of Anaheim; Cecil W. LeFevre, 3,119,736 1/1964 Clark et al 260/577X Tustin, all Of Calif. 3,546,295 12/1970 Maravetz ..260/577 3,257,1906/1966 Soper 260/577 Asslgneer United Slates Borax & Chemwfll 3,518,0766/1970 Wright ..71/121 Corporation, Los Angeles, Calif. 3,322,525 5/1967Martin et al ..71/98 [22] Flled: 1970 Primary Examiner-Lewis GottsAssistant ExaminerC. F. Warren Attorney-James R. Thornton [21] Appl.N0.: 61,449

[57] ABSTRACT US. Cl. 7 l 7 l 2 l Substituted 5-alkoxy-2-nitro-4-260/577 trifluoromethylanilines and their thio analogues. The [51] Int.Cl. ..C07c 91/42, C07c 87/58 om ounds are useful as herbicides and canbe formu- [5 Field Of Search /1 98 lated with conventional herbicidecarriers.

6 Claims, No Drawings ALKOXY TRIFLUOROMETHYLANILINE COMPOUNDS Thisinvention relates to novel alkoxy-substituted trifluoromethylanilinecompounds which are particularly useful as herbicides.

According to this invention there are provided novel compounds of theformula in which R represents alkyl of from two to about six carbonatoms, R represents hydrogen or alkyl of up to about six carbon atoms, Rrepresents lower alkyl of up to about six carbon atoms, and X is oxygenor sulfur. Typical alkyl groups represented by R and R are methyl,ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, sec-amyl, 3-pentyl, andn-hexyl. R can represent the same alkyl groups as R and R with theexception of methyl.

The 5-alkoxy-2-nitro-4-trifluoromethyanilines of this invention arereadily prepared by reaction of the corresponding5-halo-2-nitro-4-trifluoromethylaniline with an alkali metal alkoxide orthioalkoxide according to the following equation:

I CF3 in which R R R and X have the significance previously assigned, Zrepresents a reactive halogen atom such as bromine or chlorine, and Mrepresents an alkali metal such as sodium or potassium.

The reaction takes place by combining approximately equimolar amounts ofthe reactants, preferably in the presence of solvent such as an alcohol,at a temperature of from about room temperature to the refluxtemperature of the mixture, which is generally less than about 100 C.The insoluble by-product metal halide is readily separated from thereaction mixture such as by filtration and the desired product isolatedand purified by conventional procedures such as distillation underreduced pressure. The desired compounds are either high-boiling liquidsor crystalline solids which can be recrystallized from a suitablesolvent.

The metal alkoxide is prepared by well-known procedures such as byaddition of metallic sodium or potassium to the selected alcohol. Theintermediate 5- halo-2-nitro-4-trifluoromethylaniline can be prepared byreaction of about equimolar amounts of the selected organic amine with2,4-dihalo-5-nitrobenzotrifluoride. 2,4-Dihalo-5-nitro-benzotrifluoride,in turn, is readily prepared by nitration of the corresponding 2,4-dihalobenzotrifluoride such as described by French Pat. No. 745,293 (SeeChem. Abstracts 24, 4414).

The following examples illustrate preparation of representativecompounds of the present invention.

EXAMPLE I N-sec-butyl-5-ethoxy-2-nitro-4- trifluoromethylaniline To amixture of 2.98g. (0.01 mole) of N-sec-butyl-S-chloro-2-nitro-4-trifluoromethylaniline in 20 ml. of absolute ethanolwas added a solution of 0.23g. (0.01 g. atom) of sodium in 10 ml. ofabsolute ethanol. The mixture was heated in a sealed tube at C.overnight (15 hours) then cooled. The solvent was evaporated off underreduced pressure and the residue dissolved in ether. An insoluble solid(NaCl) was filtered off and the ether solution was evaporated to give3.03g. (99 percent) of product as an orange-brown oil. The assignedstructure was supported by infrared and NMR analysis. The materialsolidified on standing, m.p. 4449 C.

EXAMPLE ll N,N-Di-n-propyl-5-methoxy-2-nitro-4- trifluoromethyl-anilinewas prepared by reaction of N,N-di-n-propyl-S-chloro-2-nitro-4-trifluoromethylaniline with sodium methoxide in methanol according tothe procedure described above. The solvent was removed by distillationunder reduced pressure to leave the desired product as an oily residue.

EXAMPLE III N-Ethyl-S-thioethoxy-2-nitro-4- trifluoromethylaniline wasprepared by reaction of N-ethyl-S-chloro-2-nitro-4-trifluoromethylaniline with sodium thioethoxidein ethanol according to the procedure described above. The resultantproduct melts at 88-89 C.

EXAMPLE lV N-Ethyl-S-ethoxy-2-nitro-4-trifluoromethylaniline wasprepared by reacting N-ethylS-chloro-2-nitro-4- trifluoromethylanilinewith sodium ethoxide in ethanol as described above. The resultantproduct melts at l2 l-l22 C. after recrystallization from ethanol.

Other compounds according to the present invention which can be preparedby the procedures described above includeN,N-diethyl-5-n-propoxy-2-nitro-4- trifluoromethylanilineN-methyl-N-ethyl-S-ethoxy-2-nitro-4- trifluoromethylanilineN-sec-pentyl-S-thioethoxy-2-nitro-4- trifluoromethylanilineN-n-heXyl-N-methyl-S-thiomethoxy-2-nitro-4- trifluoromethylanilineN,N-di-ethyl-5-n-butoxy-2-nitro-4- trifluoromethylaniline.

The compounds of the present invention are useful as herbicides and areespecially useful as selective herbicides for controlling weeds indesirable crops. They can be applied as either a pre-emergence orpost-emergence treatment at a rate of from about one-half to 20 poundsper acre and preferably at a rate of about I to 5 pounds per acre. Thecompounds are used to control the growth of weeds by applying aphytotoxic amount to the locus of the weeds such as the soil in whichthe weeds are growing or will grow or to the foliage of the growingplants. Weeds, as used herein, is meant to include any plant growthwhich is undesirable.

The following example illustrates the herbicidal activity ofrepresentative compounds of this invention.

EXAMPLE V TABLEl Compound Activity SB L M N,N-di-n-propyl-5-methoxy-2nitro-d-trifluorornethylaniline O l 5 6 N -sec-butyl-5 -ethoxy-2-nitro-4-trifluoromethylaniline 0 3 8 9 N-ethyl-5-ethoxy-2-nitro-4- trifluoromethylaniline 0 0 5 6 SB soy beans 0 oats VL velvet leafM millet Since arelatively small amount of one or more of the active alkoxy anilinesshould be uniformly distributed over the area to be treated,thecompounds preferably are formulated with conventional herbicide:carriers, either liquid or a solid. Thus, the compounds can beimpregnated on or admixed with a finely divided solid car- 'rier such asclay, vermiculite, calcium carbonate, and

the like. Alternatively, the compounds can be dissolved or suspended ina liquid carrier such as water, kerosene, alcohols, xylene, benzene,glycols, ketones, and the like. A surfactant-preferably is included toaid in dispersion, emulsification and coverage. The surfactant can beeither ionic or non-ionic and may be liquid or a solid. The use of theterm surfactant herein is intended to include compounds commonlyreferred to as wetting agents, dispersing agents, and emulsificationagents. Typical surfactants include the alkylarylsulfonates, the fattyalcohol sulfates, sodium salt of naphthalenesulfonic acid, alkylarylpolyether alcohols, long chain quaternary ammonium compounds, sodiumsalts of petroleum-derived alkylsulfonic acids, polyoxyethylene-sorbitanmonolaurate, and the like. These dispersing and wetting agents are soldunder numerous trademarks and may either'be' pure compounds, mixtures ofcompounds of the same general group, or they may be mixtures ofcompounds of different classes. Surfactants can also be included incompositions containing a solid inert carrier.

Concentrated formulations containing the active agent which can besubsequently diluted, as with water, to the desired concentration forapplication to plants and soil are also provided. The advantages of suchconcentrates are that they are prepared by themanufacturer in a formsuch that the user need only mix them with a locally available carrier,preferably water,

thereby keepin shipging costs to a minimum while providing a pro uct w10 can be used with a minimum of equipment and effort. Such concentratesmay contain from about 5 to about 99 percent by weight of one or more ofthe active alkoxy anilines with a carrier or diluent, which may be asolid or liquid. Liquid carriers which are miscible with the activeagent or other liquids in which the compound may be suspended ordispersed can be used. A surfactant is also generally included tofacilitate such dilution or dispersion in water. However, the surfactantitself may comprise the carrier in such concentrates.

The herbicidal compositions can include other beneficial adjuvants, suchas humectants, oils and contact agents. Also other herbicides, such asthe sodium borates, sodium chlorate, chlorophenoxyacetic acids,

substituted uracils and ureas, carbamates, amides, and

haloalkanoic acids, can be included in the formulations.

Various changes and modifications of the invention can be made and, tothe extent that such variations incorporate the spirit of thisinvention, they are intended to be included within the scope of theappended claims.

What is claimed is:

1. A compound of the formula wherein R, is alkyl of from two to aboutsix carbon atoms, R is selected from hydrogen and lower alkyl of one toabout six carbon atoms, R, is lower alkyl of one to about six carbonatoms, and X is selected from oxygen and sulfur.

2. A compound according to claim 1 in which X is anN-ethyl-5-thioethoxy-2-nitro-4-

1. A compound of the formula
 2. A compound according to claim 1 in whichX is an oxygen atom.
 3. A compound according to claim 1 in which R1 issec-butyl and R2 is hydrogen. 4.N-sec-butyl-5-ethoxy-2-nitro-4-trifluoromethylaniline. 5.N,N-di-n-propyl-5-methoxy-2-nitro-4-trifluoromethylaniline.